This invention pertains to overbased phenates and sulfonates that contain mixtures of bases, which exhibit anti-wear properties. This invention also pertains to lubricant compositions containing the mixed base phenates and sulfonates.
Various additives can be added to lubricating oils in order to improve various oil properties. Anti-wear agents are intended to decrease wear of machine parts. Additives have been and continue to be developed for use in such oil compositions to improve the lubricating characteristics thereof and thereby to lessen the wear of the moving parts.
Lubricating oils tend to deteriorate under the conditions of use in present day automotive engines, with attendant formations of sludge and lacquer and resinous materials which adhere to the engine parts, thereby lowering the operating efficiency of the engine. Detergents and dispersants are added to the lubricating oil to keep the deposit forming materials suspended in oil so that the engine is kept clean and in efficient operation condition for extended periods of time.
Some common additives used in lubricating oils are metal sulfonates and phenates. In many cases, these additives are overbased, that is, contain a molar excess of base over that needed to neutralize the sulfonic acid or phenolic material. Overbased metal sulfonates are commonly used in lubricating oil compositions as rust inhibitors and detergents. Overbased phenates, including sulfurized phenates, are commonly used in lubricating oil compositions as detergents and antioxidants.